1. Field of the Invention
This invention relates to optical fibre cables, that is to say cables incorporating one or more optical fibres, and also to optical fibres for use therein.
2. Description of Related Art
One problem which has been experienced with optical fibre cables is a gradual increase in transmission losses for certain wavelengths with age.
It has been found that this is caused, at least in part, by the gradual absorption of hydrogen by the fibres, even where they are provided with protective coatings of synthetic plastics material, the hydrogen being initially present within the cable or being gradually evolved within the cable during its life. An object of the invention is to provide a way of alleviating this problem.